The Elder Scrolls V: Skyrim

Okay. So I walked into Riften hoping to start my Dark Brotherhood career and get married when I walked into the Bee and Barb and I talked to Louis Letrush. Me and him went on for a while. But then just afterwards he attacked me for no discernable reason. Annnd I can't go back into Riften without him attempting to kill me. Please help meh! D:>